AU783782B2 - Cushion - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): PARNHAM ASSOCIATES PTY LTD A.C.N. 005 403 074 Invention Title:

CUSHION

The following statement is a full description of this invention, including the best method of performing it known to me/us: 2

CUSHION

This invention relates to a cushion.

The invention may be said to reside in a cushion including; a first layer of low resilient foam; a second layer of low resilient foam; and a layer of high resilient foam sandwiched between the first and second layers, the first and second layers being adhered to the layer of high resilient foam.

The cushion according to this embodiment of the invention greatly improves pressure distribution when the cushion is used as a seat by distributing the pressure over a greater area compared to conventional cushions which merely comprise a single foam layer usually of resilient foam.

In the preferred embodiment of the invention the layer of resilient foam comprises a layer of high density resilient foam.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings in which; Figure 1 is a side view of a cushion in embodying the invention; Figure 2 is a perspective view of the cushion of Figure; Figure 3 is a top view of the cushion of Figure 1; Figure 4 is a bottom view of the cushion of Figure 1; Figure 5 is a front view of the cushion of Figure 1; Figure 6 is a back view of the cushion of Figure 1; \\melb-files\homeS\Luisa\Keep\Speci\Parnh PR5398 Coa1ete.doc 9/05/02 3 Figure 7 is a diagram illustrating distribution of pressure when the cushion of Figure 1 is in use; and Figure 8 is a diagram illustrating distribution of pressure in a conventional cushion.

In the preferred embodiment of the invention the cushion is generally square in plan view. However, other shapes could be used if desired. The cushion includes a first layer 10 of low resilient foam which forms an upper surface of the cushion and a second layer 12 of low resilient foam which forms the lower surface of the cushion. A layer of high density high resilient foam 14 is sandwiched between the layers 10 and 12. In the preferred embodiment of the invention the layers 10 and 12 preferably have a thickness of about 2.75cm and the layer 14 a thickness of about 2cm.

The most common application of the cushion according to the preferred embodiment is as a seat which may be incorporated into a chair or other apparatus, or may be used simply as a portable cushion upon which a person can sit when required.

In the preferred embodiment of the invention the layer 14 is viscoelastic foam which conforms to the shape of a persons anatomy and retains that shape when a person sits on the cushion and which only slowly recovers to an equilibrium position. The layers 10 and 12 tend to disburse the pressure and spread the pressure of a person's weight on the cushion over the entire cushion rather than concentrating the load at one or two points of the cushion as in conventional cushions.

The layers 10 and 2 which are formed from low resilient foam material, reduces bounce and tends to absorb shock to a much greater extent than high resilient foam from which layer 14 is formed. The lower resilient foam deforms \\melbl files\homeS\Luisa\Keep\Speci \Parnhw= PR5398 Couplete.doe 9/05/02 4 under the weight of a user to make an impression in the upper layer 10 which, due to the low resilient nature of the upper layer 10 and layer 12, takes a predetermined amount of time to disappear when the user moves as the low resilient material tends to return to its original position. The relatively slow recovery time for the low resilient material to return to its original configuration more evenly applies pressure to a user, particularly as the user changes the position and therefore reduces pressure points. Slow recovery time of the low resilient material also reduces the rebound effect to absorb shock to eliminate or greatly reduce the tendency of bounce as a person moves on the cushion. Thus, the tendency of the cushion to push-back against a user is reduced. Thus, pressure applied to the user due to the tendency of the resilient material to return to its original position is better distributed than in the case of cushions which have an upper layer formed from high resilient material or are completely formed from high resilient material. The low resilient foam material is also most preferably temperature sensitive so it tends to soften when it gets warmer and firmer when cooled. This also assists in support characteristics during sleep.

The layer 14 of high density high resilient foam provides strength to the cushion and also provides a load bearing layer to which loads are distributed by the layers 10 and 12.

As shown in Figure 7, the cushion is deformed to match the user's anatomy 20. The arrows in Figure 7 represent the pressure distribution which because the layers 10 and are low resilient and do not recover quickly and tend to deform rather than collapse at the points where greatest load occurs, tends to distribute the pressure over the cushion rather than concentrating the pressure at a particular point.

\\melbfies\hoeS\Luisa\Keep\Speci\Parnha PR5398 Conpete.doc 9/05/02 5 Figure 8 shows a diagram similar to Figure 7 but of a conventional cushion formed from a single layer of conventional usually high density resilient foam and which the pressure is usually concentrated at the points of greatest load when a person sits on the cushion.

Thus, the cushion according to the preferred embodiment of the invention is more comfortable and better supports a user than conventional cushions. A cushion also, because of the better support, intends to encourage better posture to improve natural alignment of the spine when a person is seated.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

\\melb..iles\homeS\Luisa\Keep\Speci\Parnham PR5398 Complete.doc 9/05/02

Claims (3)

1. A cushion including; a first layer of low resilient foam; a second layer of low resilient foam; and a layer of high resilient foam sandwiched between the first and second layers, the first and second layers being adhered to the layer of high resilient foam.

2. The cushion of claim 1 wherein the layer of resilient foam comprises a layer of high density resilient foam.

3. A cushion substantially as hereinbefore described with reference to the accompanying drawings. Dated this 9th day of May 2002 PARNHAM ASSOCIATES PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia \\melbtfiles\homeS\Lisa\eep\Speci\Parnha PR5398 Corf1ete.doc 9/05/02